• On Dashboard, search “Sales Invoice List” in the universal  Search bar and select it (as shown in figure)

• Following page will open with all the invoices created.
  You can select the invoice against which you need to create a “Credit Note”

Note:You will not be able to create a credit note if the invoice is in “Draft Stage”

Make sure to submit the invoice to create a credit note for the same

• Open the concerned invoice and Click on “Return/Credit Note” under ”Make” option (as shown in figure)

Once you click on “Return/Credit Note” under ”Make” option you will be able to make the following changes:

• Invoice Date: Date on which you want to make the credit note 
• Customer Address: Address of the customer, if the credit note has to be issued for a different address.
  If the address does not exist you can create a new address in same way as we create address for customer during sales invoice creation

Refer article: "How to Add Customer Address during sales invoice" creation to know the process in detail

• Currency:You can change the currency if the credit note has to be issued in some other currency
• Items/Charges/Head: You can either change the amount of the existing items or add new items or delete existing items 
  Your Charges/Item/Head would now be shown in negative sign (-ve) along with amount (as shown in figure)

Taxes and charge amount would also be shown in negative sign (-ve) along with amount (as shown in figure)

• Once your credit Note is created for the concerned invoice, your outstanding would be shown as zero (as shown in figure)
  

Note: Your series changes automatically with credit note series.
In case you want to raise a "Partial Credit Note" (Against a particular amount) you can enter that amount and a partial credit note would be automatically created

• Once you have made the changes click on  “Save" 

You will see a pop-up appear to confirm creation of "Credit Note" (as shown in figure)

• Click “Yes” to confirm and credit a “Credit Note”(as shown in figure)

• Once you confirm the status of your invoice will change to "Return" and an automated series of the credit note will also be issued ( as shown in figure)